Cecil, If it helps, I used a b.c. of .530 for the M41 that I have...no lot date...but it's a spitzer, slight boat tail, nickle clad (?) closely resembling physically the Old Sierra 140, even though the M41 weighs 144 gr. In my opinion, exact b.c. is not as critical as an accurate velocity from YOUR rifle. Don't try to use Hornady's new 4DOF calculator. Use an old reloading manual or one of the old online calculators, I think. Pretty good ammo, got some 9 inch 5 shot groups at 600 yards in a Carl Gustav '96 under ideal conditions, but more to your point, .530 got me awful close to the aiming point at extended ranges. Don't ask me why, possibly elevation above sea level (3500'), the M41 shot flatter than the sight graduations. Hope this helps. Flintlocke (Paul)
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